The Branch's primary goal in this project is to collect, analyze, and publish data based on a series of annual interviews of young women (aged 14 to 21 on January 1, 1979) regarding their pregnancy outcome and the first year of life of the child. This survey allows analysis of trends over time in the maternal and child health field of, for example, the use of obstetric technology (diagnostic ultrasound, amniocentesis, etc.), and patterns in breast-feeding. This survey has been collecting data on the youth cohort sample in relation to their employment, and work history, military service, educational attainments, etc. The Biometry & Mathematical Statistics Branch (BMSB) began collecting data on pregnancy outcome and the first year of life of the child in 1983. With this six year data base, analysis of trends over time in the maternal and child health will be done. The BMSB has joined in the funding of the data collection effort together with the Demographic and Behavioral Sciences Branch, Center for Population Research, NICHD. The mechanism of support for the field study is through an Inter Agency Agreement with the Department of Labor.